1. Technical Field
The present disclosure relates to an image generating system, an image generation method, and an imaging element, and a recording medium.
2. Description of the Related Art
Optical microscopes have been used to observe microstructure of objects, such as biological tissue. Optical microscopes utilize light that has passed through or been reflected by an object being observed. Observers observe an image enlarged by lenses.
Imaging systems not using lenses have also been proposed. Japanese Unexamined Patent Application Publication (Translation of PCT Application) No. 2013-508775 discloses a lens-free imaging system for imaging a cytological sample (FIG. 1). In this system, a holder holding a sample is positioned above an imaging sensor array. The sample held by the holder is irradiated with light from above, and light that has passed through the sample is incident on the imaging sensor array.
Recently, techniques for observing microstructure using CIS (Contact Image Sensing) have been attracting attention. In CIS, an object being observed is positioned in proximity to an imaging surface of an image sensor. In general, a two-dimensional image sensor including many photoelectric converters arranged in a matrix on the imaging surface is used as the image sensor. The photoelectric converters, typically photodiodes formed on a semiconductor layer or a semiconductor substrate, receive incident light and generate electric charge.
An image sensor includes many unit regions (unit pixel cells) each including a photoelectric converter. An image obtained by an image sensor is constituted by many pixels each representing a pixel value obtained by the photoelectric converter of a corresponding one of the unit pixel cells. Accordingly, resolution (resolving power) of a two-dimensional image sensor is usually dependent on the array pitch of the photoelectric converters on the imaging surface. Herein, resolution that is determined by the array pitch of the photoelectric converters is also referred to as “intrinsic resolution” of the image sensor. Since the array pitch of the photoelectric converters has become as small as approximately a wavelength of visible light, it is difficult to further increase the intrinsic resolution.
Techniques for realizing a resolution exceeding the intrinsic resolution of an image sensor have been proposed. Japanese Unexamined Patent Application Publication No. 62-137037 discloses a technique of generating an image of an object by using a plurality of images of the object that are obtained by shifting the image formation position of the object.